#include <bits/stdc++.h>
using namespace std;
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
using ll = long long;
#define int long long
const int N = 1e5 + 10;
int a[N];
int n, m;
bool check(ll x)
{
    int cnt = 0;
    for (int i = 1; i <= n; i++)
    {

        int distance = a[i] - a[i - 1]; // 4
        cnt = cnt + ceil(double(1.0 * distance) / double(1.0 * x)) - 1;
    }
    return cnt <= m;
}
void solve()
{

    cin >> n >> m;
    m++;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
    }
    sort(a + 1, a + n + 1);
    int l = 1, r = 1e8;
    while (l < r)
    {
        int mid = (l + r) / 2;
        if (check(mid))
        {
            r = mid;
        }
        else
        {
            l = mid + 1;
        }
    }
    cout << l << endl;
    return;
}
signed main()
{
    int t = 1;
    // cin >> t;
    while (t--)
    {
        solve();
    }
    return 0;
}
